The present invention relates to an electromagnetic clutch/brake device. More particularly, it relates to a structure for preventing a rattling movement of a rotary brake of the electromagnetic clutch/brake device.
The conventional electromagnetic clutch/brake device is so constructed that a rotary brake is slidable on an output shaft by actuating electromagnetically an exciter coil to be magnetically coupled to a stationary brake whereby the output shaft is braked.
Thus, in the conventional device, the rotary brake is connected to the output shaft through a spline structure so as to be slidable in its axial direction with the result that when the output shaft is coupled to an electromagnetic clutch unit but is free from engagement with an electromagnetic braking unit and if the output shaft is subjected to substantial variations in its revolution speed, a rattling movement is caused between the rotary brake and the output shaft at the connecting portion to the spline thereby generating uncomfortable noise.
It is an object of the present invention to overcome the disadvantage of the conventional device and to provide an electromagnetic clutch/brake device for eliminating noise caused by the rattling of a rotary brake by shifting the rotary brake with respect to an output shaft so that a gap produced at the spline-connection portion is given on one side in the radial direction. More specifically, the rotary brake is so constructed as to be unbalanced in weight with respect to its center while a rotary body driven by the actuation of an electromagnetic clutch is made unbalanced in weight so as to cancel the unbalanced condition of the rotary brake thereby providing as a whole a balanced rotating condition between the rotary brake and the rotary body on the output shaft.